Whats your .02? Designing first build

I know a lot of these probably get posted. I have had an electric smoker for last few years but ended up melting it this last winter after putting a blanket and plastic bag over it to hold heat. I am looking for an efficient design for a UDS. Please give me your .02 and if its out of the norm of everyone else please provide me reasoning as to why you think its a better option.

Valve location and design?

30 vs 55 gallon drum?

Domed lid vs flat drum lid that comes with it?

Basket material, design and size?

Dimensions for mounting the racks? I would like to get two racks in it.

Any links and pictures would be very much appreciated.

Thanks in advance, I am excited to get this build planned and built over next few weeks.

In looking at a drum with a lid and locking ring. Dave does the extension do anything more than add more cooking space?

Nope.... Just adds height to the cooking space.... Some folks find more room above coals for the first rack is necessary for good heat distribution.... then to have 2 racks with adequate room for turkeys for example.... the extension can be added at any time.... if you make the exhaust holes near the top of the sides, when the extension is added, it covers those holes and new exhaust holes can be added...
When building the charcoal basket, check folks builds...... the baskets usually have at least 4" of space under them for ash collection... then is the basket is 8" tall, + the 4" legs, and then a perforated heat shield above the basket, + the drip pan etc...... a lot of internal space has been used... little room for big hunks of meat..... at least that is what some folks have found....
Just don't want you to build one without looking at all the possibilities.....

So what does everyone feel is a suffiecient height? I would like to have 2 racks. Tall enough for a chicken on each. If i do a turkey will only be a single. How about exhaust size? Fire basket deminsions? Height, width, any materials besides expanded wire? Anyone ever insulated a UDS? I was thinking some fiberglass insulation then a stainless shell on the outside. Or even better would be about 1-1/2" gap between drum and outside shell and fill in with sand. Be super heavy but would hold heat like a beast. I like the extension idea but it would have to go directly on top of the drum and be flush so there is not an overlap of the extension ring and drum on the inside. Mostly just a visual thing. I think my buddies and I are going to enter our first smoking competition at the end of june. Its small but should be fun.

Alright got my drum bought yesterday and dropped off to the sand blaster yesterday afternoon. Went and bought just about all the other supplies last night. Bought a cheap $40 grill from Home Depot which I will use lid, grate, and deciding of fire basket if I use charcoal ring or not. I bought a cheap pizza pan from walmart which I will create my 3-4" spacing between it and my fire basket using 5-1/2" bolts. I also bought a cheap non-stick cooking WOK that I am going to use as my diffuser/drip pan/water pan if I decide I want to go water route. I bought a second grate to add in. I am going to run 3 3/4" intakes. Two will be on each side with caps and third will be front and center with T fitting to allow for a cap and a 18" vertical rise for my valve. I will paint with high temp engine paint on the outside and season the inside.

Ive seen some pictures of adjustable shelving people have used but couldnt find it at Home depot?

Whats an efficient fire basket size?

Whats a good thermometer set up? brand and where to locate it and how in the smoker?

A UDS is one of the most fuel efficient smokers you can build. My charcoal basket is 12" tall, 15" round, I filled it with Kingsford blue bag and some oak chunks (probably about 3/4 of the way full, after 9 hours of cooking at 300 degrees, I still had half of the original fuel I started with.

A UDS does not need to be insulated, however I have seen a few where they dropped a 30 gallon inside a 55 gallon and insulated it, but to me it is not necessary. For more cook space go with the 55, I have a 15 gallon also at home, you can do a chicken or 5 or 6 burgers, but it's real limited.

A UDS can hold quite a bit of food if you have the domed lid, without it, you will compromise some cook space, but it still works just fine.

For the diffuser, buy another pizza pan, the perforated style, works like a champ. Or just buy one of the charcoal diffusers for the Old Smokey brand grills, works well too.

My basket...

Hard to tell from the pic, but the handle also doubles as a spot for my diffuser to rest. After making the cross handle, I added a pin to the top, drilled a hole in the center of the perforated pizza pan to hold it in place while cooking.

I had similar goals. I wanted two racks, an ash pan under my charcoal basket, a basket that could hold enough charcoal for a long burn 12-16 hours, and more. I also wanted elevated ball valves for air flow control, casters making it easier to move around, some form of handle for the basket so I wouldn't get grease all overmyself trying to get the basket in/out, I didn't want to HAVE to use a difuser or water pan so I knew I needed 24" between the bottom of the basket and my lower rack, and I needed to do all this without welding. Overall it came out really well. If you want more detailed instructions than I provided in the thread, PM me and I can send you all the nitty gritty stuff. Others have asked so I have it all typed up if you want I can forward it to you.

Looks like im going to get to build my UDS and hopfully smoke something on sunday.

My layout is as follows:
55 gallon drum fully sandblasted
22.5" webber dome lid with standard vent for now
buying a maverik dual probe thermometer off amazon this weeknd
2 22.5" grates
3-1" air intakes
-2 that are capped on a 90 degree street elbow
-third is going to be on a 90 degree street elbow with a 30" rise to a 1" brass ball valve with a SS u-bolt for support.
I have a 3' x 3' piece of heavy expanded metal to make fire basket still debating on final size and shape. round or square. input?????
I am using a 16" pizza pan as my ash try which will be attached to my fire basket with ss 1/4" bolts with a 3-4" gap between the two
Using a 16" WOK as my diffuser /drip pan. too big? will it deflect too much from the meat?